Objective:

2

To characterize and compare the chemical information of four extracts of Qingre Chushi (QRCS) decoction by liquid chromatography-mass spectrometry (LC-MS)

and combine the chemical information of the four extracts with their results of anti-inflammatory effect for a multivariate statistical analysis

in order to identify the compounds directly relating to the anti-inflammatory effects of QRCS decoction.

Method:

2

Four extracts of QRCS decoction were characterized by UPLC-Q-TOF-MS: ①ethanol extract+ water extract

② ethanol extract+ supernatant after water extraction and alcohol precipitation

③ ethanol extract+ precipitation after water extraction and alcohol precipitation

and ④ standard decoction. On the basis of the results of inhibition of the four above extracts on xylene-induced ear swelling in mice

multivariate statistical analysis [principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA)] were carried out to lock the chromatographic peaks with significant differences between group ① (the best pharmacological action group) and group ④ (standard decoction group). According to the accuracy of quasi-molecular ion and fragment ion data

and the reference materials and literature data

those chromatographic peaks were identified.

Result:

2

PCA could cluster the four extracts of QRCS decoction

and the differences between groups was reflected in the distance between groups. Group ④ (standard decoction) had the most significant differences with the other three groups

especially in the first principal component; group ① (ethanol extract+ water extract)

group ② (ethanol extract+ supernatant after water extraction and ethanol precipitation) and group ③ (ethanol extract+ precipitation after water extraction and ethanol precipitation) had certain differences in the second principal component. OPLS-DA was used to compare group ① (the best pharmacological action group) and group ④ (standard decoction group). Eleven chromatographic peaks with great contribution and high reliability to group differences

were identified as gentiopicrin

skimmin

baicalin

baicalin isomer

wogonoside

5

6

7-trihydroxy-8-methoxyflavone-7-

O

-glucurodonaldehyde

5

6-dihydroxy-6

8

2′

3′-tetramethoxyflavone

salicin-6-

C

-arabinose-8-

C

-glucoside

plantamajoside and glycyrrhizic acid.

Conclusion:

2

In the mode of pectrum-effect combination

this study explores and identifies compounds relating to the anti-inflammatory effect of QRCS decoction

so as to provide the basis for screening the extraction and purification process and optimizing the formulation of preparation of Qingre Chushi decoction.